Imagine that you’re stationed at a lunar colony, some decades in the future, when your moon monkey wrench breaks. You have two choices: wait for a replacement tool in the next cargo shipment a month away, or just make one on the spot. The do-it-yourself option recently got a boost, when researchers demonstrated the feasibility of 3-D custom parts printing using raw materials available on the moon.

The team, which included researchers from NASA and Washington State University, worked with a 3-D printer that melts powdered feedstock with lasers and then layers the melted powder into solid structures. Real lunar regolith is too precious to melt down, so they fed the printer with imitation lunar soil—a close chemical match to the real thing.

The printed parts are still a bit rough around the edges, though—they resemble rusty lengths of iron. One of the team members remarked that “It doesn’t look fantastic, but you can make something out of it.”